Qt 5.1(.1) migration plans and blockers

Saucy feature freeze is here, but there are known bugs with Qt 5.1 (ppa:canonical-qt5-edgers/qt5-beta-proper) / Qt 5.1.1 (ppa:canonical-qt5-edgers/qt5-beta2). Qt 5.1.1 snapshots are essentially identical to final tarballs being released.